Method and apparatus for heating shoe elements for the bonding thereof



Oct. 13, 1970 c. R. DINOLFO ETAL 3,533,117

METHOD AND APPARATUS FOR HEATING SHOE ELEMENTS FOR THE BONDING THEREOF IFiled Jan. 30, 1968 2 Sheets-Sheet 1 mvmroas.

CHARLES 2. 01/001. F0 3y 205E121 LEHR ATTORNEY Oct. 13, 1970 c. R.DINOLFO ETAL 533,117

METHOD AND APPARATUS FOR HEATING SHOE ELEMENTS FOR THE BONDING THEREOFFiled Jan. 30, 1968 2 Sheets-$heet 2 i i m- '7 l g 2 115 s Z i a; :"jIll- I E "I i mwzmoxs.

CHARLES R. DINOLFO y ROBERT M. LEI/R ATTORNEY United States PatentOffice 3,533,117 Patented Oct. 13, 1970 3 533,117 METHOD AND APPARATUSFOR HEATING SHOE ELEMENTS FOR THE BONDING THEREOF Charles R. Dinolfo,181 Bay 28th St., Brooklyn, N.Y.

11214, and Robert M. Lehr, 11 E. 86th St., New York, N.Y. 10028 FiledJan. 30, 1968, Ser. No. 701,606 Int. Cl. A43d 11/00 US. Cl. 12-142 7Claims ABSTRACT OF THE DISCLOSURE A method and apparatus for selectivelyheating shoe uppers and soles for the bonding of the same on an assemblyline basis. A plurality of matched shoe upper and sole pairs arearranged in columns on a conveyor belt which transports each columnthrough its respective oven corridor wherein each sole and selectedportions of the upper are subjected to successive stages of anglecontrolled infrared heat beams. The oven corridors are staggered in thedirection of travel of the conveyor belt so that the heat treated shoeuppers and soles emerge from the oven in staggered locations along theconveyor belt, to thereby facilitate the unloading of each individualcolumn of shoe upper and sole pairs by a single operator stationedalongside the conveyor belt.

The present invention relates to a method of shoe manufacture and moreparticularly to an assembly line method for heat treating shoe uppersand soles prior to assembly thereof, during the course of themanufacturing process, and the apparatus therefor.

High volume shoe production is recognized as an area where massproduction techniques can contribute significantly to cost reduction,which is a very important factor, particularly in the highly competitivelow priced shoe field.

In a typical shoe manufacturing process wherein the method of thepresent invention finds particular application, a shoe upper is fittedon a shoe last to maintain its proper shape, an insole is placed on thesole of the last and the lower peripheral portion of the upper is foldedover the insole and secured thereto by means of suitable adhesive. Theadhesive coated sole and the sole portion of the upper and insole arethen heated, after which the sole is secured to the upper in a bondingoperation.

In presently employed methods of shoe production each sole and shoeupper is individually handled by a series of operators during thevarious stages of assembly of the shoe upper with the sole. Suchconventional methods suffer from the fact that excessive manual labor isrequired for the various shoe assembly operations, thus contributingsubstantially to the cost of'shoe production.

(It is therefore an object of the present invention to provide a methodfor automating the shoe upper and sole assembly operation by making theshoe upper and sole heat treatment process suitable for mass productionand to thereby obtain the attendant cost reduction.

It is a further object of the present invention to provide a method forconveying multiple lines of shoe uppers and soles simultaneously throughrespective oven corridors, each providing for selectively heating theuppers and soles to the proper temperatures for bonding, the corridorsbeing so arranged as to permit the heated uppers and soles to beunloaded and bonded in an eflicient manner by a minimum number ofoperators.

It is another object of the present invention to pro vide an apparatusfor accomplishing the foregoing objects.

In accordance with the principles of the present invention there isprovided a method for heat treating shoe uppers and soles on a massproduction basis with a minimum number of operators. A plurality of shoeupper and sole pairs are arranged in rows and columns on a horizontalconveyor belt. While on the conveyor belt, adhesive is applied to thesole, and in the case of fabric uppers, to the upper as well. Eachcolumn of shoe upper and sole pairs is continuously and simultaneouslyconveyed through its respective parallel oven corridor Wherein each soleand selected portions of the upper are subjected to successive stages ofangle controlled infrared heat beams. The oven corridors are parallellyarranged and are staggered in the direction of travel of the conveyorbelt so that the heat treated shoe uppers and soles emerge from the ovenin staggered locations along the conveyor belt, to thereby facilitatethe unloading of each column of shoe upper and sole pairs by a singleoperator stationed alongside the conveyor belt. Upon removal from theconveyor belt each heat treated sole is secured to its correspondingheat treated upper by means of a press, in a bonding operation.

The features of the invention which are believed to be novel are setforth with particularity in the appended claims. The invention itself,however, both as to its organization and method of operation, togetherwith further objects and features thereof may best be understood byreference to the following description taken in conjunction with theaccompanying drawings wherein:

FIG. 1 is a perspective View of a shoe upper and a fragmentary view of asole to be heat treated and secured thereto in accordance with theprinciples of the present invention;

FIG. 2 is a perspective view of a portion of the apparatus for carryingout the method of the present invention, with a part of the apparatusbroken away and shown in section;

FIG. 3 is a top plan view of the apparatus shown in FIG. 2; and

FIG. 4 is an enlarged sectional view of the apparatus taken along line44 of FIG. 3.

Referring to FIG. 1, in preparation for heat treatment as hereinafterdescribed, a shoe upper 10 is fitted on a shoe last 12, and its lowerperipheral edge 14- is folded over the peripheral portion of an insole16 and secured thereto by means of suitable adhesive to form a shoeupper assembly 18. An outer sole 20 is provided, to be secured toperipheral edge 14 of upper 10 and insole 16, after having been heattreated in accordance with the principles of the present invention ashereinafter described. In the case of shoes having vinyl uppers, onlysole 20 is coated with adhesive, whereas in the case of fabric uppers,both sole 20 and the fabric upper portion 14 are cemented.

The general objective of the present invention is to provide a method ofheat treating shoe upper assembly 18 and sole 20 for assembly on a massproduction basis. For this purpose, referring to FIGS. 2 and 3, there isprovided an oven 22 divided into parallel elongated oven corridors A, B,C and D, with each oven corridor being further divided into foursections, e.g. A-l, A-2, A-3, and A-4, each containing a heating elementfor successively subjecting each shoe pair, consisting of an upperassembly 18 and sole 20, to four successive heating stages ashereinafter described. In order to feed the shoe upper and soles throughthe various successive heating stages, there is provided a horizontalconveyor belt 24, mounted on a supporting work table (not shown).Conveyor belt 24 may be regarded as divided into four parallel tracks A,B, C', and D aligned with the respective oven corridors, A, B, C, and D.The upper assembly 18 and sole 20 pairs are arranged in columns oncon-veyor belt 24 with each column on its corresponding track, so thatone column of upper assembly 18 and sole 20 pairs is transported throughits respective oven corridor, wherein they are subjected to the abovementioned successive heating stages. The successive heating stagesselectively heat the adhesive coated sole 20 and the folded portion 14of the upper causing the adhesive to set, so that upon emergence fromoven 22, each heat treated upper assembly 18 and sole 20 may be pressedtogether in a bonding operation.

As shown in FIGS. 2 and 3, the pair of inner oven corridors B and Cwhich are in lateral alignment, are longitudinally offset from outeroven corridors A and D, the latter corridors also being in lateralalignment with each other. This staggered configuration of the ovencorridors realizes an important feature of the present invention,whereby the upper assembly and sole pairs emerge from their respectiveoven corridors in staggered positions on conveyor belt 24. Thisarrangement permits the unloading of an outer column of shoe uppers andsoles, e.g. on track A, by one operator, and the unloading of the otherinner column, e.g. track B, by a second operator stationed further alongconveyor belt 24. This arrangement eliminates any possible interferencebetween operators, who Would otherwise have to be stationed at the samelocation to unload the two columns of shoe uppers and soles 'which wouldbe emerging from oven 22 at the same time.

The loading and heat treatment process will now be described in detail.Referring to FIG. 2, the matched pairs of lasted upper assemblies 18 andsoles 20 are loaded on conveyor belt 24 at loading station 26,comprising a frame 28 supporting vertical partitions 30, 32, and 34.These partitions form loading stalls for ensuring that the matched pairsare loaded on conveyor belt tracks A, B, C, and D in alignment with therespective oven corridors A, B, C, D. Operators stationed at the end ofthe table, for example at stations 38 and 40 shown in FIG. 3, load thematched shoe pairs in rapid succession within the various loading stallsdefined within frame 28.

In loading the shoe pairs, each lasted upper assembly 18 is seated onthe conveyor belt 24 with the side of the shoe upper 10 resting on thetop surface of belt 24 in such a manner that the insole 16 is positionedat a slight angle to the vertical and is facing the adjacent edge of theconveyor belt 24. Thus, in FIG. 4 it will be observed that the two shoeuppers 18 on conveyor belt tracks A and B are so inclined that theirinsoles face the right hand side of the conveyor belt, while the insolesof the shoe uppers on conveyor belt tracks C and D face the left handside of the conveyor belt. Further, in each matched pair, thecorresponding outer sole 20 is placed flat on conveyor belt 24,alongside and slightly spaced from the lasted upper assembly 18. In eachinstance, the outer sole 20 is placed on the side of the correspondingupper assembly 18 in the direction of the adjacent edge of the conveyorbelt 24, as shown in FIGS. 1 and 4.

After loading, the columns of upper assembly and sole pairs aretransported by conveyor belt 24 in the direction of arrow 42 (FIGS. 2and 3) toward the respective oven corridors A, B, C, D to be subjectedto the successive heating stages. During such travel, operatorsstationed at the sides of the conveyor belt between the loading station26 and the oven entrances, apply coatings of adhesive or cement to thelasted upper assembly 18 as well as the outer sole 20 of each matchedshoe pair.

Each of the oven corridors A, B, C, and D comprises four successiveheater stages, e.g. in corridor A, stages Al, A2, A3, and A4, forsequentially heating each upper assembly 18 and/or sole 20 ashereinafter described.

As best shown in FIG. 4, each heating stage comprises a horizontallydisposed linear type infrared heat lamp 44 partially surrounded by aparabolic reflector 46 for controllably projecting an angle controlledheat beam 48 to 4 preselected portions of the upper assembly 18 and/orsole 20.

As shown in FIG. 4, each of the linear infrared heat sources 44 isoffset sideways from its corresponding conveyor belt track so that theheat beam 48 emanating therefrom is oriented angularly toward saidcorresponding track. Thus, each heat beam is adapted to impinge on thefolded-over portion 14 of the upper 10 which is positioned at a slightangle to the vertical, as well as upon the horizontally-disposed sole20, as required in the particular heating stage. The housing for oven 22comprises rectangular section enclosures 50, 52, 54, and 56 forming ovencorridors A, B, C, and D respectively, and a pair of inwardly-inclinedside walls 58 and 60 extending from outer walls 62 and 64 of outercompartments 50 and 56 to adjacent the side edges of conveyor belt 24.

A central partition 66 is provided between tracks B and C, as shown inFIG. 4, to prevent overlapping of the heat beams emanating from theinner corridors B and C. In addition, suitable exhausts (not shown) maybe provided for removal of hot air that is generated during the heatingprocess.

The successive heating steps will be described for oven corridor A, itbeing understood that the heating process is identical in the other ovencorridors, B, C, and D.

In the first heating stage, e.g. stage Al, reflector 46 is so shaped andoriented as to provide an infrared heat beam 48 directed to avoid upperassembly 18 and to impinge only on sole 20. In this stage heat beam 48is at a temperature of 110 F. Thus, as assembly 18 and sole 20 aretransported through first heating stage Al, only sole 20 is heated. Thisfirst stage is indicated in FIG. 4 with relation to the stage C-l whichis identical to stage Al.

Conveyor belt 24 continues to transport the upper assembly 1-8 and sole20 pair through the second heating stage, i.e. stage A2, where aninfrared heat beam at approximately 110 F. is directed at both sole 20and folded-over portion 14 of upper 10, as well as the exposed portionof insole 16. This is illustrated for stage B-2 in FIG. 4. It will benoted that the heat beam does not impinge upon the side and top portionof the upper assembly. In this way, the adhesive which had previouslybeen applied to folded-over portion 14 of upper 10 and to sole 20 sets,i.e., dries.

The upper assembly 18 and sole 20 are then further transported through athird heating stage, i.e., stage A3, where only the folded-over portion14 of upper 10 as well as the insole 16 are flash heated at a hightemperature, i.e., approximately 200 F. This stage is exemplified by bystage D-3 shown in FIG. 4, wherein it will be noted that the heat beamavoids the outer sole 20. In this Way, folded-over portion 14 of theupper becomes hot, but not so hot as to cause it to separate from theinsole 16- i.e., to cause popping. During this heating stage theinfrared heat beam is again focussed and directed to impinge only oninsole 1 6 and folded-over portion 14, while avoiding the remainingportions of upper 10.

Conveyor belt 24 continues to transport upper assembly 1 8 and sole 20through a fourth heating stage A4, illustrated in FIG. 4, which issimilar to stage A3, and wherein the heating process of stage A3 isrepeated, that is to say, the lower surface of upper assembly 18 issubjected to flash heat at relatively high temperature.

It is to be understood that the apparatus of the present invention isnot limited to the specific dimension of the conveyor belt 24 or oven22. However, by Way of example, in one suitable arrangement, conveyorbelt 24 has an overall length of approximately feet and a width of about40 inches. In this arrangement, the oven 22 has an overall length of 22feet, with each oven corridor being 14 /3 feet long, and each heatingstage is about 3% feet in length. Each oven corridor is approximatelyone foot wide. Conveyor belt 24 may have a selectively variable speed offive to fifteen feet per minute with a typical average speed of 10 feetper minute, in which case the time cycle, i.e. the total heat treatmentperiod for each shoe upper and sole, is approximately one minute twentyseconds.

Control of the infrared heat beam angular orientation and beam width inthe various heating stages A-l A-4, may be accomplished by means ofadditional reflectors (not shown) which may be located below linearinfrared heat lamp 44 and which serve to selectively direct therespective heat beams 48 solely onto folded upper portion 14, or solelyupon sole 20, as the case may be.

Since the beam width and angular orientation of heat beam 48 are preset,it is important that upper assembly 18 and sole 20 of each matched pairbe accurately positioned in their proper track when being loaded atstation 26, so that they will receive the proper degree of heat from thevarious beams 48 as they are transported through the oven 22 by means ofconveyor belt 24.

It will now be approciated that as each matched pair is transportedthrough the oven 22, it is subjected to a continuous heating operationin which relatively low heat is applied to the outer sole 20 over arelatively long period (i.e., two stages) for drying the cement thereon.Thereafter, the upper assembly, which has been preheated, is subjectedto a short period of relatively intense heat so that the cement driesand sets, and the upper becomes sufiiciently hot to permit thesubsequent bonding operation. As soon as the upper assembly and matchedouter sole emerge together from the oven, an operator applies the outersole to the heated upper assembly under pressure in a power press. Thehot upper assembly heats and plasticizes the adhesive coating on theouter sole, resulting in firm bonding of the completed shoe parts.

In practice, at one side of conveyor belt 24, a first operator islocated at unloading station 66, adjacent the area in which the heatedshoe pairs emerge from oven corridor A. This operator removes the shoepairs as fast as they emerge from corridor A and is provided with apower press for bonding the outer sole 20 to the upper assembly 1 8while the latter is still hot. A second operator is located on the sameside of the conveyor belt at unloading station 70 adjacent the area inwhich heated shoe pairs emerge from the oven corridor B, the station 70being further along the conveyor belt. This second operator is alsoprovided with a power press which he uses to bond the shoe pairs removedfrom the conveyor belt as fast as they emerge from oven corridor B. Thebonding operation is duplicated on the opposite side of the conveyorbelt 22 by another pair of operators located at unloading stations 68and 72 for bonding the shoe pairs emerging from the respective ovencorridors D and C.

Thus, the staggered or oflFset relationship of the oven corridors A, B,C, D in conjunction with the single conveyor belt realizes an importantfeature of the invent1 on whereby the bonding operators may each servicean individual oven corridor Without interfering with each other. In thismanner a smooth rapid, and highly eflicient unloading and bondingoperation is efiected.

A heel- (not shown) may be suitably secured to the heel portion of sole20, in any well known manner, prior to the loading of sole 20 onconveyor belt 24. In this way the bonding operation described above willcomplete the shoe assembly operation.

A preferred embodiment of the invention has been shown and describedherein. It will be obvious that numerous omissions, changes andadditions may be made in such embodiment without departing from thespirit and scope of the invention.

What we claim is:

1. A method of shoe manufacture comprising loading a plurality of lastedshoe uppers and matched soles on transport means with each shoe upperbeing paired with a corresponding sole for assembly therewith, applyingadhesive to each of said soles, transporting said sole and said shoeupper pairs in unison through an oven, projecting angle controlled heatbeams onto each of said soles and a pre-selected portion of each of saidshoe uppers while said soles and shoe uppers pass through said oven, tothereby condition said soles and shoe uppers for securing each of saidsoles to its said paired shoe upper after emergence of each of saidupper and said sole pairs from said oven, said shoe upper and sole pairsbeing disposed on said transport means in a plurality of columns forsimultaneous transport of said columns through said oven, with the upperand sole pairs of each of said columns being successively subjected to aseries of heat beams spaced apart in said oven, while travelling throughsaid oven, each of said soles being positioned proximate to and intransverse alignment with its paired shoe upper on said transport means,and the first heat beam of said series being projected upon the uppersurface of said sole and being of sufficient temperature to dry and setthe adhesive on said sole.

2. A method as defined in claim 1 wherein the second heat beam of saidseries is at approximately the same temperature as said first beam andis projected onto the lower surface of said lasted upper and onto saidupper surface of said sole.

3. A method as defined in claim 2 wherein the third and fourth heatbeams of said series are at a relatively high temperature and areprojected solely upon the lower surface of said lasted upper.

4. A method as defined in claim 3 wherein an individual heat beam seriesis provided for each of said columns of shoe pairs, the beams of atleast some of said series being in longitudinally offset and staggeredrelationship to the beams of other series, whereby the shoes of thecorresponding columns emerge at different locations from theirrespective heat beam series.

5. Apparatus for shoe manufacture comprising conveyor belt means fortransporting matched pairs of shoe uppers and soles placed thereon alongselected longitudinal tracks, an enclosed oven overlying said conveyor'belt means and comprising a series of elongated oven corridors extendinglongitudinally of said conveyor belt means, each of said oven corridorsbeing disposed above and in substantial longitudinal alignment with acorresponding one of said conveyor belt tracks, each oven corridorcontaining a plurality of heating elements arranged in a longitudinalseries to provide selectively variable heat beams directed at thealigned conveyor belt track, whereby when said matched pairs of shoeuppers and soles are disposed on said conveyor belt means to form paircolumns transported along respective belt tracks, said heating elementsof the series contained in the aligned oven corridor are operative toapply heat to each of said soles and preselected portions of each ofsaid shoe uppers in success1ve stages as said columns are transportedpast the correponding longitudinal series of heating elements, each ofsaid oven corridors comprising a plurality of successive longitudinallyarranged heating stages, each of said heating stages containing one ofthe heating elements of a longitudinal series, each heating elementbeing operative to produce a heat beam of a pre-selected temperature andbeing adjustable for selective variation of the angular orientation andwidth of said heat beam, whereby said shoe upper and sole pairs aresuccessively subjected to variously adjusted heat beams as each of saidcolumns is transported through its respective oven corridor.

6. Apparatus as defined in claim 5 wherein each of said heating elementscomprises a longitudinal heat source and reflector means operative toform the heat rays emanating from said source into a heat beam whoseangular orientation and beam width is selectively variable.

7. Apparatus as defined in claim 5 wherein said oven is formed of afirst pair of centrally located corridors and a second pair of ovencorridors bracketing said first pair and located outwardly thereof, thecorridors of said first pair being in lateral alignment with each otherand the corridors of said second pair being in lateral alignment with 7each other, the first of corridors being laterally offset and staggeredwith respect to said second pair.

References Cited UNITED STATES PATENTS 8 3,220,033 11/1965 Bromfield eta1 121 3,256,420 6/1966 Werman 121 X FOREIGN PATENTS 842,170 7/1949Germany.

PATRICK D. LAWSON, Primary Examiner US. Cl. X.R. 121

